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  Subjects -> VETERINARY SCIENCE (Total: 193 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brno     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 7)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 9)
American Journal of Primatology     Hybrid Journal   (Followers: 6)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 15)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 136)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Nutrition     Open Access   (Followers: 3)
Animal Reproduction Science     Hybrid Journal   (Followers: 6)
Animals     Open Access   (Followers: 5)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (Followers: 7)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 6)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 2)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 4)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 3)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 1)
Bangladesh Veterinarian     Open Access   (Followers: 1)
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 6)
Case Reports in Veterinary Medicine     Open Access   (Followers: 4)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 5)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 2)
Equine Health     Full-text available via subscription   (Followers: 1)
Equine Veterinary Education     Hybrid Journal   (Followers: 8)
Equine Veterinary Journal     Hybrid Journal   (Followers: 10)
Ethiopian Veterinary Journal     Open Access   (Followers: 4)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Frontiers in Veterinary Science     Open Access  
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
InVet     Open Access  
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 2)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 4)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 10)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 2)
Journal of Experimental and Applied Animal Sciences     Open Access  
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 1)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 8)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 21)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 2)
Journal of the Selva Andina Research Society     Open Access  
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 5)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 10)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 12)
Journal of Veterinary Medical Education     Partially Free   (Followers: 9)
Journal of Veterinary Medicine     Open Access   (Followers: 4)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 2)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 4)
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 1)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 1)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 3)

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Journal Cover   Veterinary Microbiology
  [SJR: 1.425]   [H-I: 84]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [2812 journals]
  • Isolation of canine Anaplasma phagocytophilum strains from clinical blood
           samples using the Ixodes ricinus cell line IRE/CTVM20
    • Abstract: Publication date: 23 March 2013
      Source:Veterinary Microbiology, Volume 162, Issues 2–4
      Author(s): Viktor Dyachenko , Christine Geiger , Nikola Pantchev , Monir Majzoub , Lesley Bell-Sakyi , Inke Krupka , Reinhard K. Straubinger
      Anaplasma phagocytophilum is an intracellular tick-borne rickettsial pathogen, which causes granulocytic anaplasmosis in various species of livestock and companion animals and also in humans. Previously A. phagocytophilum has been isolated and propagated in cell lines derived from the tick Ixodes scapularis and in the human promyelocytic cell line HL60. In this study we used the Ixodes ricinus-derived cell line IRE/CTVM20 to isolate and propagate two new canine strains of A. phagocytophilum. Blood samples were collected by veterinarians from two dogs, one from Germany and the other from Austria. Suspicion of clinical canine granulocytic anaplasmosis was raised by the treating veterinarians and after confirmation of A. phagocytophilum infection by real-time PCR, buffy coat cells were isolated and co-cultivated with IRE/CTVM20 cells maintained at 28°C in L15/L15B medium. In the tick cells, rickettsial inclusions were first recognised after 86 days of incubation. Electron microscopic examination of tick cells infected with one of the isolates revealed cytoplasmic vacuoles containing pleomorphic organisms with individual bacteria enveloped by a bilayer membrane. Sequencing of 16S rRNA genes confirmed the isolation of A. phagocytophilum and showed the highest identity to the A. phagocytophilum human HZ strain. The two A. phagocytophilum isolates were passaged several times in IRE/CTVM20 cells and transferred to the I. scapularis cell line ISE6. This confirms for the first time the successful establishment and continuous cultivation of this pathogen in I. ricinus cells as well as infectivity of these canine strains for I. scapularis cells.


      PubDate: 2015-05-21T11:50:33Z
       
  • Modulation of chemokine and chemokine receptor expression following
           infection of porcine macrophages with African swine fever virus
    • Abstract: Publication date: 23 March 2013
      Source:Veterinary Microbiology, Volume 162, Issues 2–4
      Author(s): Emma Fishbourne , Charles C. Abrams , Haru-H. Takamatsu , Linda K. Dixon
      African swine fever virus (ASFV) is the only member of the Asfarviridae, a large DNA virus family which replicates predominantly in the cytoplasm. Most isolates cause a fatal haemorrhagic disease in domestic pigs, although some low virulence isolates cause little or no mortality. The modulation of chemokine responses following infection of porcine macrophages with low and high virulence isolates was studied to indicate how this may be involved in the induction of pathogenesis and of effective immune responses. Infection with both low and high virulence isolates resulted in down-regulation of mRNA levels for chemokines CCL2, CCL3L, CXCL2 and chemokine receptors CCR1, CCR5, CXCR3, CXCR4 and up-regulation in expression of mRNAs for CCL4, CXCL10 and chemokine receptor CCR7. Levels of CCL4, CXCL8, CXCL10 mRNAs were higher in macrophages infected with low virulence isolate OURT88/3 compared to high virulence isolate Benin 97/1. Levels of CXCL8 and CCL2 protein were significantly reduced in supernatants from macrophages infected with Benin 97/1 isolate compared to OURT88/3 and mock-infected macrophages. There was also a decreased chemotactic response of donor cells exposed to supernatants from Benin 97/1 infected macrophages compared to those from OURT88/3 and mock-infected macrophages. The data show that infection of macrophages with the low virulence strain OURT88/3 induces higher expression of key inflammatory chemokines compared to infection with high virulence strain Benin 97/1. This may be important for the induction of effective protective immunity that has been observed in pigs immunised with the OURT88/3 isolate.


      PubDate: 2015-05-21T11:50:33Z
       
  • Phylogeny and prevalence of kobuviruses in dogs and cats in the UK
    • Abstract: Publication date: 28 June 2013
      Source:Veterinary Microbiology, Volume 164, Issues 3–4
      Author(s): N. Carmona-Vicente , J. Buesa , P.A. Brown , J.Y. Merga , A.C. Darby , J. Stavisky , L. Sadler , R.M. Gaskell , S. Dawson , A.D. Radford
      The kobuviruses represent an emerging genus in the Picornaviridae. Here we have used next generation sequencing and conventional approaches to identify the first canine kobuvirus (CaKoV) from outside the USA. Phylogenetic analysis suggests that a single lineage genotype of CaKoV now exists in Europe and the USA with 94% nucleotide similarity in the coding region. CaKoV was only identified in a single case from a case–control study of canine diarrhoea, suggesting this virus was not a frequent cause of disease in this population. Attempts to grow CaKoV in cell culture failed. Sequence analysis suggested CaKoV was distinct from human Aichi virus (AiV), and unlikely to pose a significant zoonotic risk. Serosurveys by ELISA, immunofluorescence and neutralisation tests, using AiV as antigen, suggested kobuvirus infection is prevalent in dogs. In addition, IgG antibody to AiV was also detected in cat sera, indicating for the first time that cats may also be susceptible to kobuvirus infection.


      PubDate: 2015-05-21T11:50:33Z
       
  • Experimental infection of white-tailed deer (Odocoileus virginianus) with
           Northern European bluetongue virus serotype 8
    • Abstract: Publication date: 25 October 2013
      Source:Veterinary Microbiology, Volume 166, Issues 3–4
      Author(s): Barbara S. Drolet , Lindsey M. Reister , Tara D. Rigg , Pauline Nol , Brendan K. Podell , James O. Mecham , Kurt C. VerCauteren , Piet A. van Rijn , William C. Wilson , Richard A. Bowen
      Bluetongue (BT) is an insect-transmitted, economically important disease of domestic and wild ruminants. Although only five of the 26 reported bluetongue virus (BTV) serotypes are considered endemic to the USA, 10 exotic serotypes have been isolated primarily in the southeastern region of the country since 1999. For an exotic BTV serotype to become endemic there must be susceptible animal species and competent vectors. In the USA, sheep and white-tailed deer (WTD) are the primary sentinel livestock and wildlife species, respectively. In 2006, BTV-8 was introduced into Northern Europe and subsequently overwintered, causing unprecedented livestock disease and mortality during the 2006–2007 vector seasons. To assess the risk of the European strain of BTV-8 to North American WTD, and understand the role they could play after a similar introduction, eight bluetongue-seronegative WTD were inoculated with BTV-8. Body temperatures and clinical signs were recorded daily. Blood samples were analyzed for BTV RNA with quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR), serum analyzed for BTV antibodies by cELISA, and tissues taken for histopathology and qRT-PCR. All eight deer became infected and developed moderate to severe clinical disease from days 8 to 15. Peak viremia was from day 7 to 10 with detectable titers through the end of the study (28 days) in most deer. Serum antibody was detected by day 6, peaked by day 10 and continued through day 28. We conclude that North American WTD are highly susceptible to BTV-8 and would act as clinical disease sentinels and amplifying hosts during an outbreak.


      PubDate: 2015-05-21T11:50:33Z
       
  • Gene expression analysis of Salmonella enterica SPI in macrophages
           indicates differences between serovars that induce systemic disease from
           those normally causing enteritis
    • Abstract: Publication date: 27 December 2013
      Source:Veterinary Microbiology, Volume 167, Issues 3–4
      Author(s): Ariel Imre , Agnes Bukovinszki , Margaret A. Lovell , Hongying Li , Xiangmei Zhou , Paul A. Barrow
      Global gene expression of the invasive Salmonella serovars S. Enteritidis and S. Typhimurium, and the less-invasive S. Infantis and S. Hadar was studied during infection of a chicken macrophage cell line. Major functional gene groups responsible for intracellular physiological changes were regulated similarly in all four serovars. However, SPI1 and SPI4 genes of S. Enteritidis and S. Typhimurium were strongly repressed in the macrophages whereas S. Infantis, S. Hadar and other similar serovars maintained up-regulation of these gene sets. This phenomenon may explain some of the biological differences between invasive and non-invasive Salmonella serovars.


      PubDate: 2015-05-21T11:50:33Z
       
  • Proteomic approach for identification of immunogenic proteins of
           Mycoplasma mycoides subsp. capri
    • Abstract: Publication date: 27 December 2013
      Source:Veterinary Microbiology, Volume 167, Issues 3–4
      Author(s): L. Corona , G. Cillara , S. Tola
      In this study, an immunoproteomic approach was used to identify immunodominant proteins from Mycoplasma mycoides subsp. capri isolates. Membrane proteins, extracted through TX-114 phase partitioning, were separated using mono- and two-dimensional electrophoresis and detected by Western blotting with pooled sera from naturally infected goats. A total of 27 immunoreactive spots, corresponding to 13 different proteins, were identified using nanoLC–ESI-MSMS. Function annotation revealed that most of these proteins were metabolic enzymes involved in carbohydrate and energy metabolism. The immunogenic proteins identified in this study: pyruvate dehydrogenase, dihydrolipoamide acetyltransferase, dihydrolipoyl dehydrogenase, phosphate acetyltransferase, phosphopyruvate hydratase, adenine phopshoribosyltransferase, transketolase, translation elongation factor G, translation elongation factor Ts, FMN-dependent NADH-azoreductase, peptide methionine sulfoxide reductase, inorganic diphosphatase and trigger factor may be used as biomarkers for the serological diagnosis of contagious agalactia caused by M. mycoides subsp. capri.


      PubDate: 2015-05-21T11:50:33Z
       
  • Genetic dissection of complete genomes of Type 2 PRRS viruses isolated in
           Denmark over a period of 15 years
    • Abstract: Publication date: 27 December 2013
      Source:Veterinary Microbiology, Volume 167, Issues 3–4
      Author(s): Lise K. Kvisgaard , Charlotte K. Hjulsager , Manreetpal Singh Brar , Frederick C.C. Leung , Lars E. Larsen
      Type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) was first detected in Europe in 1996 co-incident with the introduction of a live attenuated vaccine. Since then, only limited ORF5 and ORF7 sequences of Type 2 PRRS viruses have been reported throughout Europe. In the present study, the genetic and antigenic diversity of 11 complete genomes and 49 ORF5 and 55 ORF7 nucleotide sequences obtained from 57 viruses in Denmark from 2003 to 2012 were examined. The genetic identity of the 11 complete genomes to the vaccine strain (Ingelvac PRRS MLV) ranged between 93.6 and 99.6% while the 49 ORF5 sequences examined were 94.0–99.8% identical to the vaccine strain. Among the Danish sequences, the pairwise nucleotide identity was 90.9–100% and 93.0–100.0% for ORF5 and ORF7, respectively. Analysis of the genetic region encoding NSP2 revealed high diversity among the Danish viruses with an 86.6–98.9% range in similarity. Furthermore, several of the sequenced viruses harbored deletions in the NSP2 coding region. Phylogenetic analysis in a global Type 2 PRRSV framework classified all Danish isolates to a single cluster (sub-lineage 5.1) which comprised strains closely-related to the Type 2 prototype isolate VR2332.


      PubDate: 2015-05-21T11:50:33Z
       
  • Characterization of the in vitro core surface proteome of Mycoplasma
           mycoides subsp. mycoides, the causative agent of contagious bovine
           pleuropneumonia
    • Abstract: Publication date: 10 January 2014
      Source:Veterinary Microbiology, Volume 168, Issue 1
      Author(s): Ivanka Krasteva , Anne Liljander , Anne Fischer , David G.E. Smith , Neil F. Inglis , Massimo Scacchia , Attilio Pini , Joerg Jores , Flavio Sacchini
      Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides (Mmm) is a severe cattle disease, present in many countries in sub-Saharan Africa. The development of improved diagnostic tests and vaccines for CBPP control remains a research priority. Polyacrylamide gel electrophoresis and mass spectrometry were used to characterize the Triton X-114 soluble proteome of nine Mmm strains isolated from Europe or Africa. Of a total of 250 proteins detected, 67 were present in all strains investigated. Of these, 44 were predicted to be lipoproteins or cytoplasmic membrane-associated proteins and are thus likely to be members of the core in vitro surface membrane-associated proteome of Mmm. Moreover, the presence of all identified proteins in other ruminant Mycoplasma pathogens were investigated. Two proteins of the core proteome were identified only in other cattle pathogens of the genus Mycoplasma pointing towards a role in host–pathogen interactions. The data generated will facilitate the identification and prioritization of candidate Mycoplasma antigens for improved control measures, as it is likely that surface-exposed membrane proteins will include those that are involved in host–pathogen interactions.


      PubDate: 2015-05-21T11:50:33Z
       
  • Molecular genetic analysis of Dichelobacter nodosus proteases AprV2/B2,
           AprV5/B5 and BprV/B in clinical material from European sheep flocks
    • Abstract: Publication date: 10 January 2014
      Source:Veterinary Microbiology, Volume 168, Issue 1
      Author(s): Anna Stäuble , Adrian Steiner , Lea Normand , Peter Kuhnert , Joachim Frey
      Dichelobacter nodosus, the etiological agent of ovine footrot, exists both as virulent and as benign strains, which differ in virulence mainly due to subtle differences in the three subtilisin-like proteases AprV2, AprV5 and BprV found in virulent, and AprB2, AprB5 and BprB in benign strains of D. nodosus. Our objective was a molecular genetic epidemiological analysis of the genes of these proteases by direct sequence analysis from clinical material of sheep from herds with and without history of footrot from 4 different European countries. The data reveal the two proteases known as virulent AprV2 and benign AprB2 to correlate fully to the clinical status of the individuals or the footrot history of the herd. In samples taken from affected herds, the aprV2 gene was found as a single allele whereas in samples from unaffected herds several alleles with minor modifications of the aprB2 gene were detected. The different alleles of aprB2 were related to the herds. The aprV5 and aprB5 genes were found in the form of several alleles scattered without distinction between affected and non-affected herds. However, all different alleles of aprV5 and aprB5 encode the same amino acid sequences, indicating the existence of a single protease isoenzyme 5 in both benign and virulent strains. The genes of the basic proteases BprV and BprB also exist as various alleles. However, differences found in samples from affected versus non-affected herds do not reflect the currently known epitopes that are attributed to differences in biochemical activity. The data of the study confirm the prominent role of AprV2 in the virulence of D. nodosus and shed a new light on the presence of the other protease genes and their allelic variants in clinical samples.


      PubDate: 2015-05-21T11:50:33Z
       
  • Genetic diversity of porcine group A rotavirus strains in the UK
    • Abstract: Publication date: 17 September 2014
      Source:Veterinary Microbiology, Volume 173, Issues 1–2
      Author(s): Rebecca Chandler-Bostock , Laura R. Hancox , Sameena Nawaz , Oliver Watts , Miren Iturriza-Gomara , Kenneth M. Mellits
      Rotavirus is endemic in pig farms where it causes a loss in production. This study is the first to characterise porcine rotavirus circulating in UK pigs. Samples from diarrheic pigs with rotavirus enteritis obtained between 2010 and 2012 were genotyped in order to determine the diversity of group A rotavirus (GARV) in UK pigs. A wide range of rotavirus genotypes were identified in UK pigs: six G types (VP7); G2, G3, G4, G5, G9 and G11 and six P types (VP4); P[6], P[7], P[8], P[13], P[23], and P[32]. With the exception of a single P[8] isolate, there was less than 95% nucleotide identity between sequences from this study and any available rotavirus sequences. The G9 and P[6] genotypes are capable of infecting both humans and pigs, but showed no species cross-over within the UK as they were shown to be genetically distinct, which suggested zoonotic transmission is rare within the UK. We identified the P[8] genotype in one isolate, this genotype is almost exclusively found in humans. The P[8] was linked to a human Irish rotavirus isolate in the same year. The discovery of human genotype P[8] rotavirus in a UK pig confirms this common human genotype can infect pigs and also highlights the necessity of surveillance of porcine rotavirus genotypes to safeguard human as well as porcine health.


      PubDate: 2015-05-21T11:50:33Z
       
  • Transcriptome analysis of CNS immediately before and after the detection
           of PrPSc in SSBP/1 sheep scrapie
    • Abstract: Publication date: 10 October 2014
      Source:Veterinary Microbiology, Volume 173, Issues 3–4
      Author(s): Anton G. Gossner , John Hopkins
      Sheep scrapie is a transmissible spongiform encephalopathy (TSE), progressive and fatal neurodegenerative diseases of the central nervous system (CNS) linked to the accumulation of misfolded prion protein, PrPSc. New Zealand Cheviot sheep, homozygous for the VRQ genotype of the PRNP gene are most susceptible with an incubation period of 193 days with SSBP/1 scrapie. However, the earliest time point that PrPSc can be detected in the CNS is 125 days (D125). The aim of this study was to quantify changes to the transcriptome of the thalamus and obex (medulla) at times immediately before (D75) and after (D125) PrPSc was detected. Affymetrix gene arrays were used to quantify gene expression in the thalamus and Illumina DGE-tag profiling for obex. Ingenuity Pathway Analysis was used to help describe the biological processes of scrapie pathology. Neurological disease and Cancer were common Bio Functions in each tissue at D75; inflammation and cell death were major processes at D125. Several neurological receptors were significantly increased at D75 (e.g. CHRNA6, GRM1, HCN2), which might be clues to the molecular basis of psychiatric changes associated with TSEs. No genes were significantly differentially expressed at both D75 and D125 and there was no progression of events from earlier to later time points. This implies that there is no simple linear progression of pathological or molecular events. There seems to be a step-change between D75 and D125, correlating with the detection of PrPSc, resulting in the involvement of different pathological processes in later TSE disease.


      PubDate: 2015-05-21T11:50:33Z
       
  • Molecular characterisation of lineage IV peste des petits ruminants virus
           using multi gene sequence data
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): K. Senthil Kumar , Aravindh Babu , G. Sundarapandian , Parimal Roy , A. Thangavelu , K. Siva Kumar , R. Arumugam , N.D.J. Chandran , Murali Muniraju , Mana Mahapatra , Ashley C. Banyard , B. Murali Manohar , Satya Parida
      Peste des petits ruminants is responsible for an economically important plague of small ruminants that is endemic across much of the developing world. Here we describe the detection and characterisation of a PPR virus from a recent outbreak in Tamil Nadu, India. We demonstrate the isolation of PPR virus from rectal swab and highlight the potential spread of disease to in-contact animals through faecal materials and use of faecal material as non-invasive method of sampling for susceptible wild ruminants. Finally we have performed a comprehensive ‘multi-gene’ assessment of lineage IV isolates of PPRV utilising sequence data from our study and publically available partial N, partial F and partial H gene data. We describe the effects of grouping PPRV isolates utilising different gene loci and conclude that the variable part of N gene at C terminus gives the best phylogenetic assessment of PPRV isolates with isolates generally clustering according to geographical isolation. This assessment highlights the importance of careful gene targeting with RT-PCR to enable thorough phylogenetic analysis.


      PubDate: 2015-05-21T11:50:33Z
       
  • Pathogenicity study in sheep using reverse-genetics-based reassortant
           bluetongue viruses
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Cristina C. Celma , Bishnupriya Bhattacharya , Michael Eschbaumer , Kerstin Wernike , Martin Beer , Polly Roy
      Bluetongue (BT) disease, caused by the non-enveloped bluetongue virus (BTV) belonging to the Reoviridae family, is an economically important disease that affects a wide range of wild and domestic ruminants. Currently, 26 different serotypes of BTV are recognized in the world, of which BTV-8 has been found to exhibit one of the most virulent manifestations of BT disease in livestock. In recent years incursions of BTV-8 in Europe have resulted in significant morbidity and mortality not only in sheep but also in cattle. The molecular and genetic basis of BTV-8 pathogenesis is not known. To understand the genetic basis of BTV-8 pathogenicity, we generated reassortant viruses by replacing the 3 most variable genes, S2, S6 and S10 of a recent isolate of BTV-8, in different combinations into the backbone of an attenuated strain of BTV-1. The growth profiles of these reassortant viruses were then analyzed in two different ovine cell lines derived from different organs, kidney and thymus. Distinct patterns for each reassortant virus in these two cell lines were observed. To determine the pathogenicity of these reassortant viruses, groups of BTV-susceptible sheep were infected with each of these viruses. The data suggested that the clinical manifestations of these two different serotypes, BTV-1 and BTV-8, were slightly distinct and BTV-1, when comprising all 3 genome segments of BTV-8, behaved differently to BTV-1. Our results also suggested that the molecular basis of BT disease is highly complex.


      PubDate: 2015-05-21T11:50:33Z
       
  • Prevalence of Coxiella burnetii in environmental samples collected from
           cattle farms in Eastern and Central Poland (2011–2012)
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Agata Bielawska-Drózd , Piotr Cieślik , Tomasz Mirski , Jerzy Gaweł , Aleksander Michalski , Marcin Niemcewicz , Michał Bartoszcze , Dorota Żakowska , Krzysztof Lasocki , Józef Knap , Janusz Kocik
      Coxiella burnetii is the etiologic agent of Q fever. It may occur as two different morphological forms, a large cell variant (LCV) and a small cell variant (SCV). The SCV is characterized by unique resistance to physical and chemical factors and may survive in the environment for many months. The objective of this study was to examine environmental samples for the presence of C. burnetii using real-time PCR in areas where Q fever was previously reported and in randomly selected animal farms where Q fever was not reported. The samples were collected in the following provinces in Poland: Lublin, Subcarpathian and Masovian. Monitoring was performed with real-time PCR and serological methods. Of the 727 environmental samples, 33 (4.54%) contained the multi-copy insertion sequence IS1111, which is specific for C. burnetii. Subsequently, the presence of C. burnetii antibodies was determined using serological tests in selected herds in which positive genetic results were obtained. Serological analyses of 169 serum samples using CFT and ELISA were performed on Polish black-and-white Holstein-Friesian cows and one cow imported from Denmark. Using the CFT method, 11 samples were positive for phase I antibodies and six were positive for phase II antibodies. Moreover, in two cases, the presence of antibodies specific for both phase I and phase II antigens of C. burnetii was detected. However, of the 169 examined serum samples, 20 were positive by ELISA test, of which six were also positive by CFT. Additionally, multi spacer typing (MST) of isolated C. burnetii strains was performed. The MST results identified two new genotypes in Poland, ST3 and ST6. The results indicate that continued research regarding spread of this pathogen within a country is necessary.


      PubDate: 2015-05-21T11:50:33Z
       
  • The feline oral microbiome: A provisional 16S rRNA gene based taxonomy
           with full-length reference sequences
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Floyd E. Dewhirst , Erin A. Klein , Marie-Louise Bennett , Julie M. Croft , Stephen J. Harris , Zoe V. Marshall-Jones
      The human oral microbiome is known to play a significant role in human health and disease. While less well studied, the feline oral microbiome is thought to play a similarly important role. To determine roles oral bacteria play in health and disease, one first has to be able to accurately identify bacterial species present. 16S rRNA gene sequence information is widely used for molecular identification of bacteria and is also useful for establishing the taxonomy of novel species. The objective of this research was to obtain full 16S rRNA gene reference sequences for feline oral bacteria, place the sequences in species-level phylotypes, and create a curated 16S rRNA based taxonomy for common feline oral bacteria. Clone libraries were produced using “universal” and phylum-selective PCR primers and DNA from pooled subgingival plaque from healthy and periodontally diseased cats. Bacteria in subgingival samples were also cultivated to obtain isolates. Full-length 16S rDNA sequences were determined for clones and isolates that represent 171 feline oral taxa. A provisional curated taxonomy was developed based on the position of each taxon in 16S rRNA phylogenetic trees. The feline oral microbiome curated taxonomy and 16S rRNA gene reference set will allow investigators to refer to precisely defined bacterial taxa. A provisional name such as “Propionibacterium sp. feline oral taxon FOT-327” is an anchor to which clone, strain or GenBank names or accession numbers can point. Future next-generation-sequencing studies of feline oral bacteria will be able to map reads to taxonomically curated full-length 16S rRNA gene sequences.


      PubDate: 2015-05-21T11:50:33Z
       
  • Structural characterisation of the virulence-associated protein VapG from
           the horse pathogen Rhodococcus equi
    • Abstract: Publication date: Available online 9 February 2015
      Source:Veterinary Microbiology
      Author(s): Tebekeme Okoko , Elena V. Blagova , Jean L. Whittingham , Lynn G. Dover , Anthony J. Wilkinson
      Virulence and host range in Rhodococcus equi depends on the variable pathogenicity island of their virulence plasmids. Notable gene products are a family of small secreted virulence-associated proteins (Vaps) that are critical to intramacrophagic proliferation. Equine-adapted strains, which cause severe pyogranulomatous pneumonia in foals, produce a cell-associated VapA that is necessary for virulence, alongside five other secreted homologues. In the absence of biochemical insight, attention has turned to the structures of these proteins to develop a functional hypothesis. Recent studies have described crystal structures for VapD and a truncate of the VapA orthologue of porcine-adapted strains, VapB. Here, we crystallised the full-length VapG and determined its structure by molecular replacement. Electron density corresponding to the N-terminal domain was not visible suggesting that it is disordered. The protein core adopted a compact elliptical, anti-parallel β-barrel fold with β1–β2–β3–β8–β5–β6–β7–β4 topology decorated by a single peripheral α-helix unique to this family. The high glycine content of the protein allows close packing of secondary structural elements. Topologically, the surface has no indentations that indicate a nexus for molecular interactions. The distribution of polar and apolar groups on the surface of VapG is markedly uneven. One-third of the surface is dominated by exposed apolar side-chains, with no ionisable and only four polar side-chains exposed, giving rise to an expansive flat hydrophobic surface. Other surface regions are more polar, especially on or near the α-helix and a belt around the centre of the β-barrel. Possible functional significance of these recent structures is discussed.


      PubDate: 2015-05-21T11:50:33Z
       
  • Virulence, persistence and dissemination of Mycoplasma bovis
    • Abstract: Publication date: Available online 2 March 2015
      Source:Veterinary Microbiology
      Author(s): Sibylle Bürki , Joachim Frey , Paola Pilo
      Bovine mycoplasmosis due to Mycoplasma bovis causes several important bovine diseases such as pneumonia, mastitis, arthritis, otitis, genital disorders or keratoconjunctivitis. Variable surface lipoproteins, adhesion, invasion of host cells, modulation of the host immune system, biofilm formation and the release of secondary metabolites like hydrogen peroxide, as well as synergistic infections with other bacterial or viral pathogens are among the more significantly studied characteristics of the bacterium. The aim of this review is to summarize the current knowledge regarding the virulence of M. bovis and additionally, factors contributing to the dissemination and persistence of this pathogen in the bovine host will be discussed.


      PubDate: 2015-05-21T11:50:33Z
       
  • Characterisation of Dichelobacter nodosus and detection of Fusobacterium
           necrophorum and Treponema spp. in sheep with different clinical
           manifestations of footrot
    • Abstract: Publication date: Available online 6 March 2015
      Source:Veterinary Microbiology
      Author(s): Sara Frosth , Ulrika König , Ann-Kristin Nyman , Märit Pringle , Anna Aspán
      The aim of this study was to determine the proportion of Dichelobacter nodosus, Fusobacterium necrophorum and Treponema spp. in sheep with different clinical manifestations of footrot compared to healthy sheep both at flock and individual level. The second aim was to characterise D. nodosus with respect to virulence, presence of intA gene and the serogroups. Swab samples (n =1000) from footrot-affected (n =10) and healthy flocks (n =10) were analysed for the presence of D. nodosus, F. necrophorum and Treponema spp. by real-time PCR and culturing (D. nodosus only). Dichelobacter nodosus isolates (n =78) and positive swabs (n =474) were analysed by real-time PCR for the aprV2/B2 and the intA genes and by PCR for the fimA gene (isolates only). D. nodosus was more commonly found in flocks affected with footrot than in clinically healthy flocks. A significant association was found between feet with severe footrot lesions and the aprV2 gene and between feet with moderate or no lesions and the aprB2 gene, respectively. F. necrophorum was more commonly found in flocks with footrot lesions than in flocks without lesions. No significant association was found between sheep flocks affected with footrot and findings of Treponema spp. or the intA gene. Benign D. nodosus of six different serogroups was detected in twelve flocks and virulent D. nodosus of serogroup G in one. In conclusion, D. nodosus and F. necrophorum were more commonly found in feet with footrot than in healthy feet. The majority of D. nodosus detected was benign, while virulent D. nodosus was only detected in a single flock.


      PubDate: 2015-05-21T11:50:33Z
       
  • A new bovine conjunctiva model shows that Listeria monocytogenes invasion
           is associated with lysozyme resistance
    • Abstract: Publication date: Available online 4 March 2015
      Source:Veterinary Microbiology
      Author(s): Jessica Warren , A. Rhys Owen , Amy Glanvill , Asher Francis , Grazieli Maboni , Rodrigo J. Nova , Wendela Wapenaar , Catherine Rees , Sabine Tötemeyer
      Listerial keratoconjunctivitis (‘silage eye’) is a wide spread problem in ruminants causing economic losses to farmers and impacts negatively on animal welfare. It results from direct entry of Listeria monocytogenes into the eye, often following consumption of contaminated silage. An isolation protocol for bovine conjunctival swabbing was developed and used to sample both infected and healthy eyes bovine eyes (n =46). L. monocytogenes was only isolated from one healthy eye sample, and suggests that this organism can be present without causing disease. To initiate a study of this disease, an infection model was developed using isolated conjunctiva explants obtained from cattle eyes post slaughter. Conjunctiva were cultured and infected for 20h with a range of L. monocytogenes isolates (n =11), including the healthy bovine eye isolate and also strains isolated from other bovine sources, such as milk or clinical infections. Two L. monocytogenes isolates (one from a healthy eye and one from a cattle abortion) were markedly less able to invade conjunctiva explants, but one of those was able to efficiently infect Caco2 cells indicating that it was fully virulent. These two isolates were also significantly more sensitive to lysozyme compared to most other isolates tested, suggesting that lysozyme resistance is an important factor when infecting bovine conjunctiva. In conclusion, we present the first bovine conjunctiva explant model for infection studies and demonstrate that clinical L. monocytogenes isolates from cases of bovine keratoconjunctivitis are able to infect these tissues.


      PubDate: 2015-05-21T11:50:33Z
       
  • Resolution of the cellular proteome of the nucleocapsid protein from a
           highly pathogenic isolate of porcine reproductive and respiratory syndrome
           virus identifies PARP-1 as a cellular target whose interaction is critical
           for virus biology
    • Abstract: Publication date: 23 March 2015
      Source:Veterinary Microbiology, Volume 176, Issues 1–2
      Author(s): Long Liu , Zoe Lear , David J. Hughes , Weining Wu , En-min Zhou , Adrian Whitehouse , Hongying Chen , Julian A. Hiscox
      Porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat to the swine industry and food security worldwide. The nucleocapsid (N) protein is a major structural protein of PRRSV. The primary function of this protein is to encapsidate the viral RNA genome, and it is also thought to participate in the modulation of host cell biology and recruitment of cellular factors to facilitate virus infection. In order to the better understand these latter roles the cellular interactome of PRRSV N protein was defined using label free quantitative proteomics. This identified several cellular factors that could interact with the N protein including poly [ADP-ribose] polymerase 1 (PARP-1), a cellular protein, which can add adenosine diphosphate ribose to a protein. Use of the PARP-1 small molecule inhibitor, 3-AB, in PRRSV infected cells demonstrated that PARP-1 was required and acted as an enhancer factor for virus biology. Serial growth of PRRSV in different concentrations of 3-AB did not yield viruses that were able to grow with wild type kinetics, suggesting that by targeting a cellular protein crucial for virus biology, resistant phenotypes did not emerge. This study provides further evidence that cellular proteins, which are critical for virus biology, can also be targeted to ablate virus growth and provide a high barrier for the emergence of drug resistance.


      PubDate: 2015-05-21T11:50:33Z
       
  • Contrasting clinical outcomes in two cohorts of cats naturally infected
           with feline immunodeficiency virus (FIV)
    • Abstract: Publication date: 23 March 2015
      Source:Veterinary Microbiology, Volume 176, Issues 1–2
      Author(s): Paweł M. Bęczkowski , Annette Litster , Tsang Long Lin , Dominic J. Mellor , Brian J. Willett , Margaret J. Hosie
      Despite over 25 years of feline immunodeficiency virus (FIV) research, relatively little is known about the longitudinal course of FIV infection following natural infection. In contrast to published reports of experimental infections using lethal strains of the virus, clinical signs of naturally acquired FIV infection can be mild or inapparent, rather than life-threatening. In this prospective, longitudinal controlled study, based in Chicago, IL (n =17) and Memphis, TN (n =27), we investigated two cohorts of privately owned, naturally infected cats kept under different housing conditions. Cats in the Chicago cohort (Group 1) were kept in households of ≤2 cats, while the Memphis cohort (Group 2) comprised part of a large multi-cat household of over 60 cats kept indoors only, with unrestricted access to one another. The majority of cats from Group 1 did not display clinical signs consistent with immunodeficiency during the 22-month observation period. In contrast, the outcome of infection in Group 2 was dramatically different; 17/27 (63%) of cats lost a median of 51.3% of their bodyweight (P <0.0005) and died during the study period, with lymphoma being the most common cause of mortality. Although the decrease in CD4+ T cell count between enrolment and terminal disease was significant (P =0.0017), the CD4:CD8 ratio at the time of enrolment did not reliably distinguish FIV-positive cats classified as ‘healthy’ and ‘not healthy’ at either cohort. FIV load at enrolment was significantly lower in Group 1 than in Group 2 (P <0.0001), but there were no significant differences at enrolment between healthy and not healthy cats at either group. In conclusion, the results of this study suggest that management and housing conditions impact on disease progression and survival times of FIV-positive cats.


      PubDate: 2015-05-21T11:50:33Z
       
  • Factors affecting the infectivity of tissues from pigs with classical
           swine fever: Thermal inactivation rates and oral infectious dose
    • Abstract: Publication date: 23 March 2015
      Source:Veterinary Microbiology, Volume 176, Issues 1–2
      Author(s): Lucie Cowan , Felicity J. Haines , Helen E. Everett , Bentley Crudgington , Helen L. Johns , Derek Clifford , Trevor W. Drew , Helen R. Crooke
      Outbreaks of classical swine fever are often associated with ingestion of pig meat or products derived from infected pigs. Assessment of the disease risks associated with material of porcine origin requires knowledge on the likely amount of virus in the original material, how long the virus may remain viable within the resulting product and how much of that product would need to be ingested to result in infection. Using material from pigs infected with CSFV, we determined the viable virus concentrations in tissues that comprise the majority of pork products. Decimal reduction values (D values), the time required to reduce the viable virus load by 90% (or 1log10), were determined at temperatures of relevance for chilling, cooking, composting and ambient storage. The rate of CSFV inactivation varied in different tissues. At lower temperatures, virus remained viable for substantially longer in muscle and serum compared to lymphoid and fat tissues. To enable estimation of the temperature dependence of inactivation, the temperature change required to change the D values by 90% (Z values) were determined as 13°C, 14°C, 12°C and 10°C for lymph node, fat, muscle and serum, respectively. The amount of virus required to infect 50% of pigs by ingestion was determined by feeding groups of animals with moderately and highly virulent CSFV. Interestingly, the virulent virus did not initiate infection at a lower dose than the moderately virulent strain. Although higher than for intranasal inoculation, the amount of virus required for infection via ingestion is present in only a few grams of tissue from infected animals.


      PubDate: 2015-05-21T11:50:33Z
       
  • Understanding and managing bTB risk: Perspectives from Ireland
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Simon J. More , Margaret Good
      There is substantial variation in herd risk for bovine tuberculosis (bTB) in Ireland, with most herds playing little to no role in the ongoing endemic. In infected areas, bTB persistence (affecting one or a group of herds) is a key feature of the infection. In this paper, we present our current understanding and management of bTB risk in Ireland, based on a detailed review of research and policy. There is close interaction between science and policy in Ireland, seeking both to understand and effectively manage bTB risk. Detailed research on bTB persistence is presented, including current understanding of the relative importance of different infection sources, which can include residual infection in cattle and/or re-infection, either from local sources or following cattle introduction. In recent years, there have been three primary drivers for policy change, including scientific advances, ongoing improvements to programme supports, and ongoing programme review. In this review, three key future programme challenges are identified. Although good progress is being made, eradication has not yet been achieved. Firstly, a key question concerns the additional effort that will be required, to move towards final eradication. Secondly, a percentage of non-infected animals are falsely positive to current testing methods. This is an ongoing challenge, given the imperfect specificity of test methods but will become more so, as the positive predictive value falls with reducing bTB prevalence. Finally, there is a need to re-engage with the farming community, so that they play a much greater role in programme ownership.


      PubDate: 2015-05-21T11:50:33Z
       
  • First study of pathogen load and localisation of ovine footrot using
           fluorescence in situ hybridisation (FISH)
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Luci A. Witcomb , Laura E. Green , Leo A. Calvo-Bado , Claire L. Russell , Edward M. Smith , Rose Grogono-Thomas , Elizabeth M.H. Wellington
      Analysis of bacterial populations in situ provides insights into pathogen population dynamics and potential reservoirs for disease. Here we report a culture-independent study of ovine footrot (FR); a debilitating bacterial disease that has significant economic impact on sheep farming worldwide. Disease begins as an interdigital dermatitis (ID), which may then progress to separation of the hoof horn from the underlying epidermis causing severe footrot (SFR). Dichelobacter nodosus is the causative agent of ovine FR, however, the role of Fusobacterium necrophorum and other bacteria present in the environment and on the feet of sheep is less clear. The objective of this study was to use fluorescence in situ hybridisation (FISH) to detect, localise and quantify D. nodosus, F. necrophorum and the domain Bacteria from interdigital skin biopsies of healthy, ID- and SFR-affected feet. D. nodosus and F. necrophorum populations were restricted primarily to the epidermis, but both were detected more frequently in feet with ID or SFR than in healthy feet. D. nodosus cell counts were significantly higher in feet with ID and SFR (p <0.05) than healthy feet, whereas F. necrophorum cell counts were significantly higher only in feet with SFR (p <0.05) than healthy feet. These results, together with other published data, indicate that D. nodosus likely drives pathogenesis of footrot from initiation of ID to SFR; with D. nodosus cell counts increasing prior to onset of ID and SFR. In contrast, F. necrophorum cell counts increase after SFR onset, which may suggest an accessory role in disease pathogenesis, possibly contributing to the severity and duration of SFR.


      PubDate: 2015-05-21T11:50:33Z
       
  • Carbopol improves the early cellular immune responses induced by the
           modified-life vaccine Ingelvac PRRS® MLV
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): K.H. Mair , H. Koinig , W. Gerner , A. Höhne , J. Bretthauer , J.J. Kroll , M.B. Roof , A. Saalmüller , K. Stadler , R. Libanova
      Adjuvants enhance both the magnitude and duration of immune responses, therefore representing a central component of vaccines. The nature of the adjuvant can determine the particular type of immune response, which may be skewed toward cytotoxic T cell (CTL) responses, antibody responses, or particular classes of T helper (Th) responses and antibody isotypes. Traditionally, adjuvants have been added to intrinsically poor immunogenic vaccines, such as those using whole killed organisms or subunit vaccines. Here, we have compared cellular immune responses induced by the immunogenic modified life-attenuated vaccine Ingelvac PRRS® MLV when administered alone or in combination with carbopol, a widely used adjuvant in veterinary medicine. Using functional readouts (IFN-γ ELISpot and cell proliferation) and analyzing phenotypical hallmarks of CD4T cell differentiation, we show that carbopol improves cellular immunity by inducing early IFN-γ-producing cells and by preferentially driving T cell differentiation to effector phenotypes. Our data suggest that adjuvants may enhance and modulate life-attenuated – not only subunit/inactivated – vaccines.


      PubDate: 2015-05-21T11:50:33Z
       
  • Genetic diversity of Mycoplasma hyopneumoniae isolates of abattoir pigs
    • Abstract: Publication date: 31 January 2014
      Source:Veterinary Microbiology, Volume 168, Issues 2–4
      Author(s): Audrey Charlebois , Corinne Marois-Créhan , Pierre Hélie , Carl A. Gagnon , Marcelo Gottschalk , Marie Archambault
      Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, is present in swine herds worldwide. However, there is little information on strains infecting herds in Canada. A total of 160 swine lungs with lesions suggestive of enzootic pneumonia originating from 48 different farms were recovered from two slaughterhouses and submitted for gross pathology. The pneumonic lesion scores ranged from 2% to 84%. Eighty nine percent of the lungs (143/160) were positive for M. hyopneumoniae by real-time PCR whereas 10% (16/160) and 8.8% (14/160) were positive by PCR for M. hyorhinis and M. flocculare, respectively. By culture, only 6% of the samples were positive for M. hyopneumoniae (10/160). Among the selected M. hyopneumoniae-positive lungs (n =25), 9 lungs were co-infected with M. hyorhinis, 9 lungs with PCV2, 2 lungs with PRRSV, 12 lungs with S. suis and 10 lungs with P. multocida. MLVA and PCR-RFLP clustering of M. hyopneumoniae revealed that analyzed strains were distributed among three and five clusters respectively, regardless of severity of lesions, indicating that no cluster is associated with virulence. However, strains missing a specific MLVA locus showed significantly less severe lesions and lower numbers of bacteria. MLVA and PCR-RFLP analyses also showed a high diversity among field isolates of M. hyopneumoniae with a greater homogeneity within the same herd. Almost half of the field isolates presented less than 55% homology with selected vaccine and reference strains.


      PubDate: 2015-05-21T11:50:33Z
       
  • Correlation of cell surface marker expression with African swine fever
           virus infection
    • Abstract: Publication date: 31 January 2014
      Source:Veterinary Microbiology, Volume 168, Issues 2–4
      Author(s): Pamela Lithgow , Haru Takamatsu , Dirk Werling , Linda Dixon , Dave Chapman
      The expression of surface markers on African swine fever virus (ASFV) infected cells was evaluated to assess their involvement in infection. Previous findings indicated CD163 expression was correlated with ASFV susceptibility. However, in this study the expression of porcine CD163 on cell lines did not increase the infection rate of these cells indicating other factors are likely to be important in determining susceptibility to infection. On adherent porcine bone marrow (pBM) cells the expression of CD45 was strongly correlated with infection. CD163 and CD203a expression correlated at intermediate levels with infection, indicating cells expressing these markers could become infected but were not preferentially infected by the virus. Most of the cells expressing MHCII were infected, indicating that they may be preferentially infected although expression of MHCII was not essential for infection and a large percentage of the infected cells were MHCII negative. CD16 showed a marked decrease in expression following infection and significantly lower levels of infected cells were shown to express CD16. Altogether these results suggest CD163 may be involved in ASFV infection but it may not be essential; the results also highlight the importance of other cell markers which requiring further investigation.


      PubDate: 2015-05-21T11:50:33Z
       
  • Comparison of phenotypic and genotypic methods for the species
           identification of coagulase-negative staphylococcal isolates from bovine
           intramammary infections
    • Abstract: Publication date: 10 January 2011
      Source:Veterinary Microbiology, Volume 147, Issues 1–2
      Author(s): Joo Youn Park , Lawrence K. Fox , Keun Seok Seo , Mark A. McGuire , Yong Ho Park , Fred R. Rurangirwa , William M. Sischo , Gregory A. Bohach
      Coagulase-negative staphylococci (CNS) are the most frequently isolated pathogens from cows with intramammary infection (IMI). Although API STAPH ID 20, a commercially available identification system, and PCR-restriction fragment length polymorphism (PCR-RFLP) of the gap gene (gap PCR-RFLP) have been successfully applied for the identification of CNS isolates from human specimens, their accuracy in the identification of veterinary isolates has not been fully established. In this study, we identified 263 CNS isolates from bovine IMI at species level by partial 16S rRNA gene sequence analysis as the definitive test. Species identification obtained using partial 16S rRNA gene sequence analysis was compared to results from the API STAPH ID 20 and gap PCR-RFLP analysis. Eleven different CNS species were identified by partial 16S rRNA gene sequence analysis. Only 76.0% (200/263) of the species identification results obtained by API STAPH ID 20 matched those obtained by partial 16S rRNA gene sequence analysis, whereas 97.0% (255/263) of the species identification results obtained by the gap PCR-RFLP analysis matched those obtained by partial 16S rRNA gene sequence analysis. The gap PCR-RFLP analysis could be a useful and reliable alternative method for the species identification of CNS isolates from bovine IMI and appears to be a more accurate method of species identification than the API STAPH ID 20 system.


      PubDate: 2015-05-21T11:50:33Z
       
  • Detection of classical and newly described staphylococcal superantigen
           genes in coagulase-negative staphylococci isolated from bovine
           intramammary infections
    • Abstract: Publication date: 10 January 2011
      Source:Veterinary Microbiology, Volume 147, Issues 1–2
      Author(s): Joo Youn Park , Lawrence K. Fox , Keun Seok Seo , Mark A. McGuire , Yong Ho Park , Fred R. Rurangirwa , William M. Sischo , Gregory A. Bohach
      The coagulase-negative staphylococci (CNS) are the most prevalent mastitis pathogen group yet their virulence characteristics have not been well described. We investigated the presence of 19 classical and newly described staphylococcal superantigen (SAg) genes in CNS isolates from bovine intramammary infections (IMI). A total of 263 CNS representing 11 different Staphylococcus spp. were examined, and 31.2% (n =82) of CNS isolates had one or more SAg genes; there were 21 different SAg gene combinations. The most prevalent combination of SAg genes (seb, seln and selq; n =45) was found in S. chromogenes, S. xylosus, S. haemolyticus, S. sciuri subsp. carnaticus, S. simulans and S. succinus. The genes for SAgs appear to be widely distributed amongst CNS isolated from bovine IMI.


      PubDate: 2015-05-21T11:50:33Z
       
  • Hepatitis E virus in swine and effluent samples from slaughterhouses in
           Brazil
    • Abstract: Publication date: 21 April 2011
      Source:Veterinary Microbiology, Volume 149, Issues 1–2
      Author(s): Debora Regina Lopes dos Santos , Vanessa Salete de Paula , Jaqueline Mendes de Oliveira , Renato Sérgio Marchevsky , Marcelo Alves Pinto
      Hepatitis E is an infectious disease which virus (HEV) is highly disseminated in swine herd populations. Sporadic acute human hepatitis E cases have been associated to genotype 3 and 4 strains of HEV also reported in swine populations of endemic and non-endemic areas. With the aim to evaluate the incidence of animals with current infection of HEV, 115 bile samples were collected from three slaughterhouses under inspection by Animal Sanitary Protection Agency of Rio de Janeiro, Brazil. In parallel, effluent samples were collected from six sewage pipe exit sites of two slaughterhouses. HEV RNA was detected in 11 out of 115 (9.6%) bile samples collected and three waste samples from one slaughterhouse. Viral loads observed for bile samples varied from 101–105 genome copies/mL and for effluent samples mean load was 102 genome copies/mL. Sequencing and phylogenetic analysis classified samples within genotype 3 subtype 3b closely related to the sample obtained from the first reported autochthonous human case and samples from swine of commercial herds in Brazil. Our data demonstrates that although most animals achieve slaughter age (around 20 weeks old) already immune to HEV, a significant number of animals are with current infection at commercial age. Further studies should be addressed to consider risk analysis and possible evaluation of inspection regulations considering food safety measures regarding hepatitis E zoonotic aspect in Brazil.


      PubDate: 2015-05-21T11:50:33Z
       
  • The role of the environment in transmission of Dichelobacter nodosus
           between ewes and their lambs
    • Abstract: Publication date: Available online 22 April 2015
      Source:Veterinary Microbiology
      Author(s): Mohd Muzafar , Leo A. Calvo-Bado , Laura E. Green , Edward M. Smith , Claire L. Russell , Rose Grogono-Thomas , Elizabeth M.H. Wellington
      Dichelobacter nodosus (D. nodosus) is the essential causative agent of footrot in sheep. The current study investigated when D. nodosus was detectable on newborn lambs and possible routes of transmission. Specific qPCR was used to detect and quantify the load of D. nodosus in foot swabs of lambs at birth and 5–13h post-partum, and their mothers 5–13h post-partum; and in samples of bedding, pasture, soil and faeces. D. nodosus was not detected on the feet of newborn lambs swabbed at birth, but was detected 5–13h after birth, once they had stood on bedding containing naturally occurring D. nodosus. Multiple genotypes identified by cloning and sequencing a marker gene, pgrA, and by multi locus variable number tandem repeat analysis (MLVA) of community DNA from swabs on individual feet indicated a mixed population of D. nodosus was present on the feet of both ewes and lambs. There was high variation in pgrA tandem repeat number (between 3 and 21 repeats), and multiple MLVA types. The overall similarity index between the populations on ewes and lambs was 0.45, indicating moderate overlap. Mother offspring pairs shared some alleles but not all, suggesting lambs were infected from sources(s) other than just their mother's feet. We hypothesise that D. nodosus is transferred to the feet of lambs via bedding containing naturally occurring populations of D. nodosus, probably as a result of transfer from the feet of the group of housed ewes. The results support the hypothesis that the environment plays a key role in the transmission of D. nodosus between ewes and lambs.


      PubDate: 2015-05-21T11:50:33Z
       
  • A novel haemoplasma species identified in archived primate blood smears
    • Abstract: Publication date: 5 May 2011
      Source:Veterinary Microbiology, Volume 149, Issues 3–4
      Author(s): Emily N. Barker , Chris. R. Helps , Harold Neimark , Iain R. Peters , Wallace Peters , Séverine Tasker
      In order to confirm a microscopic diagnosis of ‘eperythrozoonosis’ made over 40 years ago in a captive owl monkey (Aotus trivirgatus), DNA was extracted from archived fixed and stained blood smears and subjected to generic haemotropic mycoplasma (haemoplasma) quantitative real-time PCR (qPCR) and a human glyceraldehyde-3-phosphate dehydrogenase qPCR as an amplification control. The qPCRs confirmed the extraction of host DNA from the samples and the presence of a haemoplasma species. Partial 16S rRNA and ribonuclease P ribosomal gene fragments were amplified by PCR, cloned and sequenced. Sequence data and phylogeny showed the owl monkey haemoplasma to lie in the haemominutum clade of haemoplasmas, most closely related to ‘Candidatus Mycoplasma kahaneii’. This study confirms the use of generic haemoplasma qPCRs to successfully amplify haemoplasma DNA from fixed, stained and archived blood smears from the early 1970s and provides molecular confirmation of the existence of a novel haemoplasma species in an owl monkey, for which the name ‘Candidatus Mycoplasma aoti’ sp. nov. is proposed.


      PubDate: 2015-05-21T11:50:33Z
       
  • First morphological characterization of ‘Candidatus Mycoplasma
           turicensis’ using electron microscopy
    • Abstract: Publication date: 5 May 2011
      Source:Veterinary Microbiology, Volume 149, Issues 3–4
      Author(s): Barbara Willi , Kristina Museux , Marilisa Novacco , Elisabeth M. Schraner , Peter Wild , Katrin Groebel , Urs Ziegler , Godelind A. Wolf-Jäckel , Yvonne Kessler , Catrina Geret , Séverine Tasker , Hans Lutz , Regina Hofmann-Lehmann
      At least three haemotropic mycoplasmas have been recognized in cats: Mycoplasma haemofelis (Mhf), ‘Candidatus Mycoplasma haemominutum’ (CMhm) and ‘Candidatus M. turicensis’ (CMt). The latter was originally identified in a Swiss pet cat with haemolytic anaemia and shown to be prevalent in domestic cats and wild felids worldwide using molecular methods. So far, there has been no confirmatory morphological evidence of the existence of CMt presumably due to low blood loads during infection while CMhm has only been characterized by light microscopy with discrepant results. This study aimed to provide for the first time electron microscopic characteristics of CMt and CMhm and to compare them to Mhf. Blood samples from cats experimentally infected with CMt, CMhm and Mhf were used to determine copy numbers in blood by real-time PCR and for transmission and scanning electron microscopy. High resolution scanning electron microscopy revealed CMt and CMhm to be discoid-shaped organisms of 0.3μm in diameter attached to red blood cells (RBCs). In transmission electron microscopy of CMt, an oval organism of about 0.25μm with several intracellular electron dense structures was identified close to the surface of a RBC. CMhm and CMt exhibited similar morphology to Mhf but had a smaller diameter. This is the first study to provide morphological evidence of CMt thereby confirming its status as a distinct haemoplasma species, and to present electron microscopic features of CMhm.


      PubDate: 2015-05-21T11:50:33Z
       
  • Phylogenetic characterisation of naturally occurring feline
           immunodeficiency virus in the United Kingdom
    • Abstract: Publication date: 2 June 2011
      Source:Veterinary Microbiology, Volume 150, Issues 3–4
      Author(s): A. Samman , E.L. McMonagle , N. Logan , B.J. Willett , R. Biek , M.J. Hosie
      Feline immunodeficiency virus (FIV) is a significant pathogen of domestic and non-domestic felids worldwide. In domestic cats, FIV is classified into five distinct subtypes (A–E) with subtypes A and B distributed most widely. However, little is known about the degree of intrasubtype viral diversity and this may prove critical in determining whether monovalent vaccines are likely to protect against FIV strains within a single subtype. Here, we characterise novel env sequences from 47 FIV strains recovered from infected cats in the United Kingdom and its environs. Phylogenetic analyses revealed that all bar one sequence belonged to subtype A, the predominant subtype in Western Europe. A single sequence was identified as a likely subtype A/C recombinant, intriguing given that subtype C does not appear to exist in either the UK or North Western Europe and suggestive of a recombination event predating its introduction into the UK. Subtype A strains from the UK were not significantly differentiated from representative subtype A isolates found elsewhere suggesting multiple introductions of FIV into the country. Divergence among isolates was comparable to that observed for subtype A isolates worldwide, indicating that FIV in the UK covers the full spectrum of subtype A diversity seen globally. This study demonstrates that while subtype A is predominant in the UK, novel introductions may result in the emergence of novel subtypes or intersubtype recombinants, potentially circumventing vaccine strategies. However, the dominance of subtype A suggests that the development of a regional or subtype-specific protective vaccine for the UK could be achievable.


      PubDate: 2015-05-21T11:50:33Z
       
  • Expression patterns of five polymorphic membrane proteins during the
           Chlamydia abortus developmental cycle
    • Abstract: Publication date: 7 December 2012
      Source:Veterinary Microbiology, Volume 160, Issues 3–4
      Author(s): Nick Wheelhouse , Michelle Sait , Kim Wilson , Kevin Aitchison , Kevin McLean , David G.E. Smith , David Longbottom
      It has been suggested that polymorphic membrane proteins (Pmps) belonging to the Type V autotransporter protein family play an important role in the pathogenesis of Chlamydia abortus (C. abortus; formerly Chlamydophila abortus) infection. In a previous study we demonstrated the expression of all the pmps at the transcriptional level. The purpose of this study was to measure the number of Pmp positive inclusions throughout the C. abortus developmental cycle to investigate heterogeneity in expression patterns. McCoy cells were infected with C. abortus and analysed for Pmp expression over a 72h period by fluorescent immunocytochemistry. Pmp18D could be detected at all analysed time points, and could only be accurately quantified from 36hpi while Pmp10G positive inclusions could be visualised from 36hpi. Expression of Pmps 13G, 16G and 17G could only be visualised later in the cycle and within less than half of visualised inclusions. These results indicate that while expression of specific Pmps is constitutive (Pmp18D), the pattern of expression of other Pmps is more variable. This suggests that different members of the Pmp family may play different roles within the developmental cycle of the organism, with some (Pmps10G and 18D) having roles throughout the cycle, while the heterogeneity of expression of others may aid in antigenic variation.


      PubDate: 2015-05-21T11:50:33Z
       
  • Intestinal and extra-intestinal pathogenicity of a bovine reassortant
           rotavirus in calves and piglets
    • Abstract: Publication date: 28 September 2011
      Source:Veterinary Microbiology, Volume 152, Issues 3–4
      Author(s): Hyun-Jeong Kim , Jun-Gyu Park , Jelle Matthijnssens , Ju-Hwan Lee , You-Chan Bae , Mia Madel Alfajaro , Sang-Ik Park , Mun-Il Kang , Kyoung-Oh Cho
      Despite the impact of bovine group A rotaviruses (GARVs) as economically important and zoonotic pathogens, there is a scarcity of data on cross-species pathogenicity and extra-intestinal spread of bovine reassortant GARVs. During the course of characterizing the genotypes of all 11 genomic segments of bovine GARVs isolated from diarrheic calves in South Korea, a unique G6P[7] reassortant GARV strain (KJ9-1) was isolated. The strain harbors five bovine-like gene segments (VP7: G6; VP6: I2; VP1: R2; VP3: M2; NSP2: N2, and NSP4: E2), five porcine-like gene segments (VP4: P[7]; NSP1: A1; NSP3: T1, and NSP5: H1), and one human-like gene segment (VP2: C2). To investigate if this reassortant strain possessed cross-species pathogenicity in calves and piglets, and could induce viremia and extra-intestinal spread in calves, colostrum-deprived calves and piglets were experimentally inoculated with the KJ9-1 strain. The KJ9-1 strain caused severe diarrhea in experimentally infected calves with extensive intestinal villous atrophy, but replicated without causing clinical symptoms in experimentally infected piglets. By SYBR Green real-time RT-PCR, viral RNA was detected in sera of the calves at post-inoculation day (PID) 1, reaching a peak at PID3, and then rapidly decreasing from PID4. In addition, viral RNA was detected in the mesenteric lymph node, lungs, liver, choroid plexus, and cerebrospinal fluid. An immunofluorescence assay confirmed viral replication in the extra-intestinal organs and tissues of virus-inoculated calves. The data indicates that the homologous/heterologous origin of the NSP4 gene segment (E2 genotype), may play a key role in the ability to cause diarrhea in calves and piglets.


      PubDate: 2015-05-21T11:50:33Z
       
  • The distribution of Aspergillus spp. opportunistic parasites in hives and
           their pathogenicity to honey bees
    • Abstract: Publication date: 14 March 2014
      Source:Veterinary Microbiology, Volume 169, Issues 3–4
      Author(s): Kirsten Foley , Géraldine Fazio , Annette B. Jensen , William O.H. Hughes
      Stonebrood is a disease of honey bee larvae caused by fungi from the genus Aspergillus. As very few studies have focused on the epidemiological aspects of stonebrood and diseased brood may be rapidly discarded by worker bees, it is possible that a high number of cases go undetected. Aspergillus spp. fungi are ubiquitous and associated with disease in many insects, plants, animals and man. They are regarded as opportunistic pathogens that require immunocompromised hosts to establish infection. Microbiological studies have shown high prevalences of Aspergillus spp. in apiaries which occur saprophytically on hive substrates. However, the specific conditions required for pathogenicity to develop remain unknown. In this study, an apiary was screened to determine the prevalence and diversity of Aspergillus spp. fungi. A series of dose–response tests were then conducted using laboratory reared larvae to determine the pathogenicity and virulence of frequently occurring isolates. The susceptibility of adult worker bees to Aspergillus flavus was also tested. Three isolates (A. flavus, Aspergillus nomius and Aspergillus phoenicis) of the ten species identified were pathogenic to honey bee larvae. Moreover, adult honey bees were also confirmed to be highly susceptible to A. flavus infection when they ingested conidia. Neither of the two Aspergillus fumigatus strains used in dose–response tests induced mortality in larvae and were the least pathogenic of the isolates tested. These results confirm the ubiquity of Aspergillus spp. in the apiary environment and highlight their potential to infect both larvae and adult bees.


      PubDate: 2015-05-21T11:50:33Z
       
  • Recombinant feline coronaviruses as vaccine candidates confer protection
           in SPF but not in conventional cats
    • Abstract: Publication date: 14 March 2014
      Source:Veterinary Microbiology, Volume 169, Issues 3–4
      Author(s): Ádám Bálint , Attila Farsang , Levente Szeredi , Zoltán Zádori , Sándor Belák
      Feline infectious peritonitis virus (FIPV) is a major pathogen of Felidae. Despite the extensive efforts taken in the past decades, development of the “ideal” live attenuated FIPV vaccine was not successful yet. In the present study, we provide data of immunisation experiments with a recombinant FCoV pair differing only in the truncation (PBFIPV-DF-2) or completion (PBFIPV-DF-2-R3i) of their ORF3abc regions. In our previous in vivo studies, these viruses proved to show the characters of low virulent or avirulent FCoV phenotypes, respectively. Therefore, we hypothesised the ability of these viruses, as possible vaccine candidates, in conferring protection in specific pathogen free (SPF) Domestic Shorthair as well as in conventional purebred British Shorthair cats. In SPF cats, after two oronasal and two intramuscular vaccinations with two weeks intervals, both vaccine candidates provided 100% protection against lethal homologous challenge with the highly virulent FIPV DF-2 strain. In contrast, the conventional purebred British Shorthair cats did not develop protection when they were immunised with the same vaccination regimes. In these groups 100% of the PBFIPV-DF-2-R3i immunised animals developed antibody-dependent enhancement (ADE). Prolonged survival was observed in 40% of the animals, while 60% showed fulminant disease course. Genetic and more probably immunological differences between the SPF and non-SPF purebred kittens can explain the different outcome of the vaccination experiment. Our data highlight the diverse immune responses between SPF and conventional cats and suggest a decisive role of previous infection by heterologous causative agents in the outcome of the vaccination against FIP.


      PubDate: 2015-05-21T11:50:33Z
       
  • Multidrug-resistant Escherichia coli from canine urinary tract infections
           tend to have commensal phylotypes, lower prevalence of virulence
           determinants and ampC-replicons
    • Abstract: Publication date: 14 March 2014
      Source:Veterinary Microbiology, Volume 169, Issues 3–4
      Author(s): Samuel Wagner , David L. Gally , Sally A. Argyle
      Multidrug-resistant Escherichia coli is an emerging clinical challenge in domestic species. Treatment options in many cases are limited. This study characterized MDR E. coli isolates from urinary tract infections in dogs, collected between 2002 and 2011. Isolates were evaluated in terms of β-lactamase production, phylogenetic group, ST type, replicon type and virulence marker profile. Comparisons were made with antibiotic susceptible isolates also collected from dogs with urinary tract infections. AmpC β-lactamase was produced in 67% of the MDR isolates (12/18). Of these, 8 could be specifically attributed to the CMY-2 gene. None of the isolates tested in either group expressed ESBLs. Phylo-group distribution was as expected in the susceptible isolates, with an over representation of the pathogenic B2 phylo-group (67%). In contrast, the phylogenetic background for the MDR group was mixed, with representation of commensal phylo-groups A and B1. The B2 phylo-group represented the smallest proportion (A, B1, B2 or D was 28%, 22%, 11% and 33%, respectively). Virulence marker profiles, evaluated using Identibac® microarray, discriminated between the two groups. Marker sequences for a core panel of virulence determinants were identified in most of the susceptible isolates, but not in most of the MDR isolates. These findings indicate that for MDR isolates, plasmid-mediated AmpC is an important resistance mechanism, and while still capable of causing clinical disease, there is evidence for a shift towards phylogenetic groups of reduced inferred virulence potential. There was no evidence of zoonotic potential in either the susceptible or MDR urinary tract isolates in this study.


      PubDate: 2015-05-21T11:50:33Z
       
  • The prevalence and genetic diversity of group A rotaviruses on pig farms
           in the Mekong Delta region of Vietnam
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Pham Hong Anh , Juan J. Carrique-Mas , Nguyen Van Cuong , Ngo Thi Hoa , Nguyet Lam Anh , Do Tien Duy , Vo Be Hien , Phan Vu Tra My , Maia A. Rabaa , Jeremy Farrar , Stephen Baker , Juliet E. Bryant
      Group A rotaviruses (ARoVs) are a common cause of severe diarrhea among children worldwide and the cause of approximately 45% of pediatric hospitalizations for acute diarrhea in Vietnam. ARoVs are known to cause significant economic losses to livestock producers by reducing growth performance and production efficiencies, however little is known about the implications of asymptomatic endemic circulation of ARoV. We aimed to determine the prevalence and predominant circulating genotypes of ARoVs on pig farms in a southern province of Vietnam. We found overall animal-level and farm-level prevalence of 32.7% (239/730) and 74% (77/104), respectively, and identified six different G types and 4 P types in various combinations (G2, G3, G4, G5, G9, G11 and P[6], P[13], P[23], and P[34]). There was no significant association between ARoV infection and clinical disease in pigs, suggesting that endemic asymptomatic circulation of ARoV may complicate rotavirus disease attribution during outbreaks of diarrhea in swine. Sequence analysis of the detected ARoVs suggested homology to recent human clinical cases and extensive genetic diversity. The epidemiological relevance of these findings for veterinary practitioners and to ongoing pediatric ARoV vaccine initiatives in Vietnam merits further study.


      PubDate: 2015-05-21T11:50:33Z
       
  • Cross-infection of virulent Dichelobacter nodosus between sheep and
           co-grazing cattle
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Maren Knappe-Poindecker , Marianne Gilhuus , Tim K. Jensen , Synnøve Vatn , Hannah J. Jørgensen , Terje Fjeldaas
      Dichelobacter nodosus is the main aetiological agent of ovine footrot and the bacterium has also been associated with interdigital dermatitis is cattle. The aim of this study was to investigate possible cross-infection of virulent D. nodosus between sheep and co-grazing cattle. Five farms, where sheep previously diagnosed with virulent D. nodosus were co-grazing with cattle for different periods of time, were included. The study sample consisted of 200 cows and 50 sheep. All cows were examined for the presence of interdigital dermatitis, and ten ewes, preferably with symptoms of footrot, had the footrot scores recorded. On each farm, the same ten ewes and ten cows were chosen for bacterial analyses. Swabs were analysed for D. nodosus by PCR and culturing. D. nodosus isolates were virulence-tested and assigned to serogroups by fimA variant determination. Biopsies were evaluated histopathologically and analysed by fluorescent in situ hybridization for D. nodosus, Treponema spp. and Fusobacterium necrophorum. D. nodosus defined as virulent by the gelatin gel test were isolated from 16 sheep from four farms and from five cows from two of the same farms. All five cows had interdigital dermatitis. Two of the cows stayed infected for at least eight months. By pulsed-field gel electrophoresis (PFGE), the isolates from the five cows were found to be genetically indistinguishable or closely related to isolates from sheep from the same farm. This indicates that cross-infection between sheep and cows have occurred.


      PubDate: 2015-05-21T11:50:33Z
       
  • Functional metagenomic analysis reveals rivers are a reservoir for diverse
           antibiotic resistance genes
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): G.C.A. Amos , L. Zhang , P.M. Hawkey , W.H. Gaze , E.M. Wellington
      The environment harbours a significant diversity of uncultured bacteria and a potential source of novel and extant resistance genes which may recombine with clinically important bacteria disseminated into environmental reservoirs. There is evidence that pollution can select for resistance due to the aggregation of adaptive genes on mobile elements. The aim of this study was to establish the impact of waste water treatment plant (WWTP) effluent disposal to a river by using culture independent methods to study diversity of resistance genes downstream of the WWTP in comparison to upstream. Metagenomic libraries were constructed in Escherichia coli and screened for phenotypic resistance to amikacin, gentamicin, neomycin, ampicillin and ciprofloxacin. Resistance genes were identified by using transposon mutagenesis. A significant increase downstream of the WWTP was observed in the number of phenotypic resistant clones recovered in metagenomic libraries. Common β-lactamases such as bla TEM were recovered as well as a diverse range of acetyltransferases and unusual transporter genes, with evidence for newly emerging resistance mechanisms. The similarities of the predicted proteins to known sequences suggested origins of genes from a very diverse range of bacteria. The study suggests that waste water disposal increases the reservoir of resistance mechanisms in the environment either by addition of resistance genes or by input of agents selective for resistant phenotypes.


      PubDate: 2015-05-21T11:50:33Z
       
  • Amelioration of salmonellosis in pre-weaned dairy calves fed Saccharomyces
           cerevisiae fermentation products in feed and milk replacer
    • Abstract: Publication date: 6 August 2014
      Source:Veterinary Microbiology, Volume 172, Issues 1–2
      Author(s): Matthew T. Brewer , Kristi L. Anderson , Ilkyu Yoon , Mark F. Scott , Steve A. Carlson
      Salmonellosis is an insidious and potentially epidemic problem in pre-weaned dairy calves. Managing this disease, or any other diarrheal disease, is a financial burden to producers. Calf mortalities and medicinal treatments are overt costs of salmonellosis, while hidden costs include hampered weight gains and persistent intestinal colonization of the pathogen. In this study, we examined the anti-Salmonella effects of Saccharomyces cerevisiae fermentation products (SCFP) incorporated into both the milk replacer and the starter grain. In a blinded study, 2–8 day-old calves were fed SCFP (n =20 calves) or an SCFP-free Control (n =20 calves) for two weeks before and three weeks after experimental challenge with Salmonella enterica serotype Typhimurium. Following the challenge, calves were monitored for clinical signs and parameters associated with salmonellosis. Calves were then euthanized and examined for rumen development and intestinal Salmonella colonization. When compared to calves that received milk replacer and feed lacking SCFP, calves fed SCFP had fewer bouts of diarrhea and fever. Rumens from these calves were more developed, as measured by the length of papillae, which is consistent with the enhanced weight gain observed in this treatment group. Additionally, Salmonella intestinal colonization was reduced in SCFP-fed calves and Salmonella fecal shedding disappeared at an earlier stage in these calves. This study revealed that the combination of two proprietary S. cerevisiae fermentation products provide marked benefit for preventing the negative effects of salmonellosis in pre-weaned dairy calves, while also boosting productivity. The mechanism of action needs to be clarified, but it may be related to the observed decrease in colonization by the pathogen and increase in rumen development.


      PubDate: 2015-05-21T11:50:33Z
       
  • High antibody titres against predicted Mycoplasma surface proteins do not
           prevent sequestration in infected lung tissue in the course of
           experimental contagious bovine pleuropneumonia
    • Abstract: Publication date: 6 August 2014
      Source:Veterinary Microbiology, Volume 172, Issues 1–2
      Author(s): Elise Schieck , Anne Liljander , Carl Hamsten , Nimmo Gicheru , Massimo Scacchia , Flavio Sacchini , Martin Heller , Christiane Schnee , Anja Sterner-Kock , Andreas Hlinak , Jan Naessens , Jane Poole , Anja Persson , Joerg Jores
      Contagious bovine pleuropneumonia (CBPP), a severe respiratory disease of cattle caused by Mycoplasma mycoides subsp. mycoides (Mmm) is endemic in many African countries due to fragmented veterinary services and the lack of an efficient vaccine and sensitive diagnostics. More efficient tools to control the disease are needed, but to develop the tools, a better understanding of host–pathogen interactions is necessary. The aim of this study was to characterize the kinetics of the humoral immune response against 65 Mmm surface antigens for an extended period in cattle that survived a primary infection with Mmm. We describe clinical and haematological outcomes, and dissect the humoral immune response over time, to specific antigens and compared the antibody responses between different pathomorphological outcomes. No antigen-specific antibodies correlating with protection were identified. Interestingly we found that animals that developed Mycoplasma-containing sequestra had significantly higher antibody levels against proteins comprising the surface proteome than the animals that cleared Mycoplasma from their lungs. Based on these data we suggest that high antibody titres might play a role in the establishment of pathomorphological changes, such as vasculitis, which should be investigated in future studies. Beneficial antibody specificities and cellular immune responses need to be identified in order to foster the development of an improved vaccine in the future.


      PubDate: 2015-05-21T11:50:33Z
       
  • VP6 genetic diversity, reassortment, intragenic recombination and
           classification of rotavirus B in American and Japanese pigs
    • Abstract: Publication date: 27 August 2014
      Source:Veterinary Microbiology, Volume 172, Issues 3–4
      Author(s): Douglas Marthaler , Tohru Suzuki , Kurt Rossow , Marie Culhane , James Collins , Sagar Goyal , Hiroshi Tsunemitsu , Max Ciarlet , Jelle Matthijnssens
      Rotavirus B (RVB) has been identified as a causative agent of diarrhea in rats, humans, cattle, lambs, and swine. Recently, 20 RVB VP7 genotypes were determined based on an 80% nucleotide percent cut-off value. In this study, we sequenced the RVB VP6 gene segment from 80 RVB positive swine samples from the United States and Japan. Phylogenetic analyses, using the 30 available RVB VP6 sequences from GenBank and our 80 novel RVB VP6 sequences, revealed a large genetic diversity of RVB strains, mainly in pigs. For classification purposes, pairwise identity frequency analyses suggested an 81% nucleotide percent cut-off value, resulting in 13 RVB VP6 (I) genotypes. In addition, an intragenic recombinant RVB VP6 segment was identified from Japan. Furthermore, the data indicates frequent reassortment events occurred between the porcine RVB VP7 and VP6 gene segments.


      PubDate: 2015-05-21T11:50:33Z
       
  • Identification and typing of Brucella spp. in stranded harbour porpoises
           (Phocoena phocoena) on the Dutch coast
    • Abstract: Publication date: 17 September 2014
      Source:Veterinary Microbiology, Volume 173, Issues 1–2
      Author(s): Elisa Maio , Lineke Begeman , Yvette Bisselink , Peter van Tulden , Lidewij Wiersma , Sjoukje Hiemstra , Robin Ruuls , Andrea Gröne , Hendrik-Ido-Jan Roest , Peter Willemsen , Joke van der Giessen
      The presence of Brucella (B.) spp. in harbour porpoises stranded between 2008 and 2011 along the Dutch coast was studied. A selection of 265 tissue samples from 112 animals was analysed using conventional and molecular methods. In total, 4.5% (5/112) of the animals corresponding with 2.3% (6/265) Brucella positive tissue samples were Brucella positive by culture and these were all confirmed by real-time polymerase chain reaction (real-time PCR) based on the insertion element 711 (IS711). In addition, two more Brucella-positive tissue samples from two animals collected in 2011 were identified using real-time PCR resulting in an overall Brucella prevalence of 6.3% (7/112 animals). Brucella spp. were obtained from lungs (n =3), pulmonary lymph node (n =3) and lungworms (n =2). Multi Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) typing based on the MLVA-16 showed that the Brucella isolates were B. ceti. Additional in silico Multi Locus Sequence typing (MLST) after whole genome sequencing of the 6 Brucella isolates confirmed B. ceti ST 23. According to the Brucella 2010 MLVA database, the isolated Brucella strains encountered were of five genotypes, in two distinct subclusters divided in two different time periods of harbour porpoises collection. This study is the first population based analyses for Brucella spp. infections in cetaceans stranded along the Dutch coast.


      PubDate: 2015-05-21T11:50:33Z
       
  • Complete genome sequence of canine astrovirus with molecular and
           epidemiological characterisation of UK strains
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Sarah L. Caddy , Ian Goodfellow
      Astroviruses are a common cause of gastroenteritis in children worldwide. These viruses can also cause infection in a range of domestic and wild animal species. Canine astrovirus (CaAstV) was first identified in the USA, and has since been reported in dogs from Europe, the Far East and South America. We sought to determine whether CaAstV is circulating in the UK dog population, and to characterise any identified strains. Stool samples were collected from pet dogs in the UK with and without gastroenteritis, and samples were screened for CaAstV by qPCR. Four CaAstV positive samples were identified from dogs with gastroenteritis (4/67, 6.0%), whereas no samples from healthy dogs were positive (p <0.001). Sequencing of the capsid sequences from the four CaAstV strains found significant genetic heterogeneity, with only 80% amino acid identity between strains. The full genome sequence of two UK CaAstV strains was then determined, confirming that CaAstV conforms to the classic genome organisation of other astroviruses with ORF1a and ORF1b separated by a frameshift and ORF2 encoding the capsid protein. This is the first report describing the circulation of CaAstV in UK dogs with clinical signs of gastroenteritis, and the first description of the full-length genomes of two CaAstV strains.


      PubDate: 2015-05-21T11:50:33Z
       
  • High prevalence and diversity of bovine astroviruses in the faeces of
           healthy and diarrhoeic calves in South West Scotland
    • Abstract: Publication date: Available online 6 May 2015
      Source:Veterinary Microbiology
      Author(s): Colin P. Sharp , William F. Gregory , Colin Mason , Barend M. deC Bronsvoort , Philippa M. Beard
      Astroviruses (AstV) are single-stranded, positive-sense RNA viruses and one of the major causes of infant diarrhoea worldwide. Diarrhoea is a common and important cause of morbidity and mortality in calves; therefore, we investigated whether the presence of AstV is associated with calf diarrhoea. We identified diverse AstV lineages from faecal samples of both healthy and diarrhoeic calves and healthy adult cattle in South West Scotland. AstV was common in calves (present in 74% (85/115) of samples) but uncommon in adult cattle (present in 15% (3/20) of samples). No association was found between the presence of AstV and calf diarrhoea or the presence of a specific AstV lineage and calf diarrhoea. AstV was strongly associated with the presence of rotavirus Group A (RVA), and a protective effect of age was evident for both AstV and RVA. Co-infections with multiple AstV lineages were detected in several calves and serial infection with different viruses could also be seen by longitudinal sampling of individuals. In summary, our study found genotypically diverse AstV in the faeces of calves in South West Scotland. However, no association was identified between AstV and calf diarrhoea, which suggests the virus does not play a primary role in the aetiology of calf diarrhoea in the group studied.


      PubDate: 2015-05-21T11:50:33Z
       
  • Exposure to environmental stressors result in increased viral load and
           further reduction of production parameters in pigs experimentally infected
           with PCV2b
    • Abstract: Publication date: Available online 20 March 2015
      Source:Veterinary Microbiology
      Author(s): Robert Patterson , Amanda Nevel , Adriana V. Diaz , Henny M. Martineau , Theo Demmers , Christopher Browne , Bettina Mavrommatis , Dirk Werling
      Porcine circovirus type 2 (PCV2) has been identified as the essential, but not sole, underlying infectious component for PCV-associated diseases (PCVAD). Several co-factors have been suggested to convert an infection with PCV2 into the clinical signs of PCVAD, including co-infection with a secondary pathogen and the genetic background of the pig. In the present study, we investigated the role of environmental stressors in the form of changes in environmental temperature and increased stocking-density on viral load in serum and tissue, average daily weight gain (ADG) and food conversion rate (FCR) of pigs experimentally infected with a defined PCV2b strain over an eight week period. These stressors were identified recently as risk factors leading to the occurrence of severe PCVAD on a farm level. In the current study, PCV2-free pigs were housed in separate, environmentally controlled rooms, and the experiment was performed in a 2×2 factorial design. In general, PCV2b infection reduced ADG and increased FCR, and these were further impacted on by the environmental stressors. Furthermore, all stressors led to an increased viral load in serum and tissue as assessed by qPCR, although levels did not reach statistical significance. Our data suggest that there is no need for an additional pathogen to develop PCVAD in conventional status pigs, and growth retardation and clinical signs can be induced in PCV2 infected pigs that are exposed to environmental stressors alone.


      PubDate: 2015-05-05T14:07:36Z
       
  • Occurrence of Clostridium botulinum neurotoxin in chronic disease of dairy
           cows
    • Abstract: Publication date: Available online 21 March 2015
      Source:Veterinary Microbiology
      Author(s): Christian Seyboldt , Sabrina Discher , Eva Jordan , Heinrich Neubauer , Katharina Charlotte Jensen , Amely Campe , Lothar Kreienbrock , Theresa Scheu , Anika Wichern , Frieder Gundling , Phuong DoDuc , Svenja Fohler , Amir Abdulmawjood , Günter Klein , Martina Hoedemaker
      Botulism caused by neurotoxins of Clostridium (C.) botulinum is a rare, but serious life-threatening disease in humans and animals. Botulism in livestock is usually caused by the oral uptake of C. botulinum neurotoxins (BoNT) via contaminated feed and is characterized by flaccid paralysis. In the recent past a new syndrome caused by BoNT in dairy cattle was postulated. It was supposed that C. botulinum is able to colonize the lower intestine and may subsequently produce neurotoxin. The continuous resorption of small amounts of these BoNT may then provoke the so called syndrome of “chronic” or “visceral” botulism involving unspecific clinical symptoms, reduced performance of dairy cows and massive animal losses in the affected herd. To test this hypothesis a case-control study was conducted involving 92 affected farms and 47 control farms located in Northern Germany. Fecal samples of 1388 animals were investigated for the presence of BoNT to verify the key requirement of the hypothesis of chronic botulism. BoNT was not detected in any of the fecal samples using the most sensitive standard method for BoNT detection, the mouse bioassay. Therefore, the existence of “chronic” or “visceral” botulism could not be proven.


      PubDate: 2015-05-05T14:07:36Z
       
 
 
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